I liked Ubuntu's approach where they asked you on startup if you want to install/enable proprietary packages like Flash or some graphics drivers.
Is it tough for Mozilla to prompt the user to do something similar with DRM stuff on first run? i.e. Telling them these are the features not supported by Mozilla in principle but are a) implemented to be in compliance with standards and b) required if you choose to use services like Netflix.
That way I would still have the option to run a DRM free browser (and voluntarily not use websites that require DRM).